Physics Ch 21 - 23 Worksheet #1
1.
Convert 16°C to Fahrenheit.
9 C 32 5 K C 273 F
Q mcT Q mL f or Q mLv 1 kg 1000 grams 1 cal 4.186 J
2.
Convert 16°F to Celsius.
J/(kg o C)
Specific Heat
3.
Convert 68°F to Kelvin.
4.
Convert 400 K to Fahrenheit.
5.
How much energy is needed to increase the temperature of 600 g of copper by 45˚C?
6.
How much energy is needed to increase the temperature of 800 grams of aluminum by 75C?
7.
How many joules of energy are needed to raise the temperature of 50 g of water from 30°C to 60°C?
8.
If 6000 J of energy are added to 800 g of silver with a temperature of 50°C, what will be the final temperature?
9.
If 3000 J of energy are removed from 2 kg of iron at a temperature 40°C, what will be the final temperature?
10. A 2 kg piece of lead has a temperature of 65°C. If 4000 J of thermal energy are added to the lead, what will be the final temperature?
water ice steam alcohol aluminum iron copper silver lead carbon glass zinc
4186 2060 2020 2450 900 448 386 230 128 710 840 388
Latent Heat of Fusion (J/kg) water lead aluminum mercury copper
3.34 x 105 2.04 x 104 3.97 x 105 1.15 x 104 2.05 x 105
(0° C) (327° C) (660° C) (-39° C) (1083° C)
Latent Heat of Vaporization (J/kg) water lead aluminum mercury copper
11. A 700 g piece of zinc at 73˚C is placed in 500 g of water at 19˚C. Find the final temperature.
12. When 250 g of an unknown material at 45°C is placed in 200 g of water at 20°C, the equilibrium temperature is 25°C. What is the unknown substance?
13. How much energy must be added to 300 g of ice at -20°C to change it to water at 25°C?
14. How much energy must be removed from 80 g of steam at 100°C to change it to water at 80°C? Answers 1. 60.8° F 2. -8.9°C 3. 293 K 4. 260.6°F 5. 10,422 J 6. 54,000 J 7. 6279 J 8. 82.6°C 9. 36.7°C 10. 80.6°C 11. 25.2°C 12. c = 837.2 so glass 13. 144,000 J 14. 187,000 J
2.26 x 106 8.64 x 106 1.14 x 106 2.72 x 106 5.07 x 106
(100° C) (1745° C) (2467° C) (357° C) (2567° C)
Physics Ch 21 - 23 Worksheet #2 9 C 32 5 K C 273 F
1.
Convert 80°F to Kelvin.
2.
Convert 250 K to Fahrenheit.
1 kg 1000 grams 1 cal 4.186 J
3.
If 3500 J of energy are removed from 500 grams of aluminum, what will be the decrease in temperature?
Specific Heat
4.
If 4500 J of energy are added to 900 grams of silver with an initial temperature of 25°C, what will be the new temperature?
5.
A 1.4 kg piece of copper has a temperature of 80°C. If placed in 800 g of water at 10C, what will be the final temperature?
6.
When 750 g of an unknown material at 95°C is placed in 300 g of water at 10°C, the equilibrium temperature is 16°C. What is the specific heat of the unknown substance?
7.
How much energy must be added to 400 g of ice at 0° C to change it to water at 30°C?
8.
How much energy must be added to 250 g of water at 55°C to change it to steam at 115°C?
9.
A 75 g piece of lead is dropped from a height of 200 m. Upon impact, all of the energy goes into the thermal energy of the lead. Find the increase in the temperature of the lead.
10. If the 75 g piece of lead hits a wall at 30 m/s and comes to a dead stop, what will be the increase in the temperature?
Q mcT Q mL f or Q mLv
water ice steam alcohol aluminum iron copper silver lead carbon glass zinc
J/(kg o C) 4186 2060 2020 2450 900 448 386 230 128 710 840 388
Latent Heat of Fusion (J/kg) water lead aluminum mercury copper
3.34 x 105 2.04 x 104 3.97 x 105 1.15 x 104 2.05 x 105
(0° C) (327° C) (660° C) (-39° C) (1083° C)
Latent Heat of Vaporization (J/kg) water lead aluminum mercury copper
11. The Yoder temperature scale has 15 for the freezing temp of water and 60 as the boiling temperature of water. Find a formula that will convert Yoder degrees to Fahrenheit degrees. 12. At what temperature is the Fahrenheit scale numerically the same as the Celsius scale?
Answers 1. 299.7 K 2. -9.4°F 3. -7.8°C 4. 46.7°C 5. 19.7°C 6. 127 J/Kg°C 7. 184,000 J 8. 620,000 J 9. 15.3°C 10. 3.5°C 11. 12.
2.26 x 106 8.64 x 106 1.14 x 106 2.72 x 106 5.07 x 106
(100° C) (1745° C) (2467° C) (357° C) (2567° C)
Physics Ch 21 - 23 Review #1 9 C 32 5 K C 273 F
1.
How much energy must be added to 200 grams of ice at -30°C to change it to water at 25°C?
Q mcT Q mL f or Q mLv
2.
How much energy must be removed from 100 grams of steam at 100°C to change it to water at 60°C?
3.
How much energy must be removed from 700 grams of water to change it from water at 10°C to ice at 0°C?
4.
Convert 15°F to Kelvin.
5.
Convert 250 K to Fahrenheit.
6.
If 3500 J of energy are removed from 500 grams of aluminum with an initial temperature of 60°C, what will be the new temperature?
7.
If 4500 J of energy are added to 900 grams of silver with an initial temperature of 25°C, what will be the new temperature?
1 kg 1000 grams 1 cal 4.186 J Specific Heat water ice steam alcohol aluminum iron copper silver lead carbon glass zinc
J/(kg o C) 4186 2060 2020 2450 900 448 386 230 128 710 840 388
Latent Heat of Fusion (J/kg)
8.
A 1.4 kg piece of copper has a temperature of 80°C. If placed in 800 g of water at 10C, what will be the final temperature?
9.
When 750 g of an unknown material at 95°C is placed in 300 g of water at 10°C, the equilibrium temperature is 16°C. What is the specific heat of the unknown substance?
10. A 60 g piece of lead is dropped from a height of 200 m. Upon impact, all of the energy goes into the thermal energy of the lead. Find the increase in the temperature of the lead.
11. If the 60 g piece of lead hits a wall at 24 m/s and comes to a dead stop, what will be the increase in the temperature of the lead?
Answers 1. 100,090 J 2. 242,744 J 3. 263,102 J 4. 263.6 K 5. -9.4°F 6. 52.2°C 7. 46.7°C 8. 19.7°C 9. 127.2 J/kg°C 10. 15.3°C 11. 2.25°C
water lead aluminum mercury copper
3.34 x 105 2.04 x 104 3.97 x 105 1.15 x 104 2.05 x 105
(0° C) (327° C) (660° C) (-39° C) (1083° C)
Latent Heat of Vaporization (J/kg) water lead aluminum mercury copper
2.26 x 106 8.64 x 106 1.14 x 106 2.72 x 106 5.07 x 106
(100° C) (1745° C) (2467° C) (357° C) (2567° C)
Physics Ch 21 - 23 Review #2 1.
When are objects in thermal equilibrium?
2.
The amount of energy needed to raise the temperature of 1 kg of a substance by 1°C is called the ______________.
3.
Do the molecules in a liquid or gas all move at the same speed or do they move at a great variety of speeds?
4.
What does temperature measure?
5.
Thermal energy flows from one object to another when there is a difference in _____________ and then this energy is called _____________.
In each, answer True or False 6.
Heat transfer by means of electrons colliding with other electrons in a metal is convection.
7.
Materials that are poor heat conductors are insulators.
8.
Heat transfer by means of atoms moving from place to place is conduction.
9.
Heat that is transferred to us from the sun is transferred by radiation.
10. All objects above 0 K radiate energy. 11. A good reflector of heat is a poor absorber of heat. 12. The rate of cooling of an object is proportional to the temperature difference between the object and its surroundings. 13. The absorption effect is the name given to the process whereby long-wavelength radiation enters a house through the windows, is absorbed and reradiated by objects in the house, and is unable to be retransmitted through the windows. 14. The average kinetic energy of molecules in a substance is related to temperature. 15. Heat is the energy that moves from one object to another because of a temperature difference. 16. The total of all energies in a substance is its temperature. 17. The amount of heat required to change the temperature of a unit mass of a substance by 1 degree is its specific heat capacity. 18. Liquids usually expand when heated. 19. Gases don't expand very much when heated. 20. A bimetallic strip consists of two strips of the same material welded together. 21. Water contracts when heated from 0 degrees C to 4 degrees C. 22. If you measure the temperature of room air, then the heat absorbed by the thermometer does not lower the air temperature noticeably. 23. A substance at a high temperature is said to contain heat. 24. The process of changing from a liquid to a gas is condensation. 25. The process of changing from a gas to a liquid is evaporation. 26. Air is saturated with water when it contains as much water vapor as it can at a given temperature. 27. Sometimes evaporation takes place at the bottom of a liquid. This process is boiling. 28. The process of changing from a liquid state to a solid state is condensation. 29. When steam changes to water at 100°C, energy is released. 30. When ice changes to water at 0°C, energy is released. 31. When evaporation and condensation have canceling effects, we say that a liquid is in saturation. 32. It is possible for water to boil and freeze at the same time.
Physics Ch 21 - 23 Review #3
Optional
1.
Convert 88°F to Kelvin.
2.
Convert 320 K to Fahrenheit.
3.
The Smith temperature scale has 50 for the freezing temp of water and 140 as the boiling temperature of water. Find a formula that will convert Smith degrees to Fahrenheit degrees.
4.
If 2500 J of energy are removed from 500 grams of aluminum that had a temperature of 70°C. What will be the new temperature?
5.
If 2800 J of energy are added to 800 grams of silver with an initial temperature of 25°C, what will be the new temperature?
6.
A 1.1 kg piece of copper has a temperature of 70°C. If placed in 400 g of water at 20C, what will be the final temperature?
7.
When 650 g of an unknown material at 105°C is placed in 200 g of water at 6°C, the equilibrium temperature is 16°C. What is the specific heat of the unknown substance?
8.
How much energy is needed to melt 75 grams of ice at 0°C?
9.
How much energy must be removed from 500 grams of water at 35°C to produce ice at -10°C?
10. How much energy must be added to 200 grams of water at 80°C to convert it to steam at 105°C?
11. 50 grams of hot water at 75°C is poured onto a large block of ice. How many grams of ice will melt? The final temperature of the water is 0°C
12. A 3 kg iron ball is dropped from a height of 50 meters. If all of the energy goes into warming ball, how much will the temperature of the ball increase?
13. A 200 gram lead object hits a hard wall at 35 m/s. If 70% of the heat generated goes into the lead, find the increase in temperature.
14. A 50 gram snow ball (ice at 0°C) is thrown at a wall. If all of the heat generated goes into the ice, how fast must the snowball be going to completely melt the ice?
15. A 30 g piece of lead is dropped from a height of 30 m. Upon impact, all of the energy goes into the thermal energy of the lead. Find the increase in the temperature of the lead.
16. If the 30 g piece of lead hits a wall at 30 m/s and comes to a dead stop, what will be the increase in the temperature?
Answers 1. 304.1 K 2. 116.6°F 3. F = 2S - 68 4. 64.4°C 5. 40.2°C 6. 30.1°C 7. c = 144.7 J/kg°C 8. 25,050 J 9. 250,555 J 10. 470,764 J 11. 0.047 kg 12. 1.1°C 13. 3.3°C 14. 817.3 m/s 15. 0.23°C 16. 3.5°C
